Spark and flame-proof exhaust outlet



March 8, 1960 w. M. SHAFFER ETA!- 2,927,422

SPARK AND FLAME-PROOF EXHAUST OUTLET Filed Sept. 23, 1957 2 Sheets-Sheet 1 WALTER M SHAFFE'R 8r WALTER z./v0m 2/s BY R/C'HEX WA r715; 06RT0M NSNENN) a FARR/NGTO/V A TTO NEYS March 8, 1960 w s E ETAL 2,927,422

SPARK AND FLAME-PROOF EXHAUST OUTLET Filed Sept. 25, 1957 2 Sheets-Sheet 2 Q @0 68 f 64 I I 2/ 48 INVENTORS W/ll 75/? M SHAF/i/Y &

2 BYWAL TEE L M02 2/5 E/C'HE): WATT); [DEERTUM M N/VY8r FARRIIYGTON ATTOR EYJ States Patent SPARK AND FLAME-PROOF EXHAUST OUTLET Walter M. Shatter, Chesterland, and Walter L. Norris, Euclid, Ohio, assignors to Towmotor Corporation, Cleveland, Ohio, a corporation of Ohio Application September 23, 1957, Serial No. 685,722

9 Claims. (Cl. 60-29) This invention relates to an exhaust outlet for internal combustion engines and more particularly to an exhaust outlet constructed and arranged so that combustible material near the engine will not be set afire by the exhaust.

Lift trucks powered by an internal combustion engine are frequently used in and around combustible material such as cotton, petroleum products and the like, and it is necessary or desirable under such conditions to provide means to prevent the exhaust from the engine setting fire to the product being handled.

Numerous expedients have been proposed to minimize the danger of fire caused by spark and flame emitted from an internal combustion engine. Such prior art devices have included screens and the like, and long tortuous passages for cooling the exhaust by ambient air before the exhaust is discharged from the exhaust pipe.

Other expedients have included exhaust arrangements where the exhaust is discharged adjacent to or beneath the level of water in an exhaust tank. Such water tank systems of flame-proofing the exhaust are adversely affected by the fact that the Water in the tank picks up corrosive materials from the exhaust, the operators frequently neglect to fill the tank and such methods often result in high back pressures adversely affecting the operation of the engine.

There are numerous conditions of engine operation which would in the absence of some flame-proofing means set fire to combustible material adjacent the exhaust. For example, when a lift truck engine is running at full speed while lifting a load on the forks the exhaust from the engine would be characterized by temperatures high enough to set fire to a bale of cotton if the exhaust were near the cotton. Under such operating conditions sparks consisting of carbon particles from the combustion cham her or the exhaust line may break off and be discharged at a temperature high enough to set fire to combustible material.

Another dangerous operating condition is that resulting from what is commonly known as after fire. Infrequently due to faulty ignition or imperfect carburation a quantity of gas may be pumped up into or accumulate in the exhaust line or muffler and upon ignition of such gas mixture a very high temperature flame is discharged at high pressures from the exhaust outlet.

According to our invention, we have provided an exhaust outlet device which eliminates the use of water tanks, screens and back pressure producing apparatus and one which will effectively prevent the discharge of sparks or flame under all operating conditions.

According to our invention a plurality of spaced relatively cool metal surfaces are disposed with respect to an exhaust outlet so that sparks and flame carried by the exhaust impinge on such cool metal surfaces and by concooling fins on the engine or theair outlet grille provides the relatively cool metal surfaces.

It is an object of our invention to provide an exhaust outlet for an internal combustion engine having a fan moving a quantity of cooling air wherein the exhaust is discharged into such cooling air whereby the exhaust is diffused and cooled to a safe temperature by said cooling air.

It is a further object of our invention to provide an exhaust outlet for an internal combustion engine having a radiator core and a fan to blow air through said core wherein the exhaust gas is distributed over a relatively large area and discharged against said radiator core and into the path of cooling air being moved through the core by the fan.

It is a further object of our invention to provide an exhaust outlet according to the preceding objects wherein the exhaust from the engine is led through a muffler and thence into an outlet pipe mounted adjacent the radiator core and wherein the pipe is provided with a number of small openings discharging sparks and flame into the core whereby such sparks and flame are extinguished by contact with the metal surfaces in the core and thereby cooled to a temperature which will not set fire to adjacent combustible material.

Further objects and advantages relating to efficiency and safe operation, simplicity of construction and low cost manufacture will appear from the following description and appended drawings, wherein Fig. l is a perspective view of a lift truck provided with an exhaust outlet according to the present invention;

Fig. 2 is an elevation through a portion of the lift truck showing the engine, fan, radiator and the exhaust outlet mounted in front of the radiator according to the present invention;

Fig. 3 is an enlarged sectional showing taken on the plane indicated at 3-3 of Fig. 1;

Fig. 4 is a plan view of an air-cooled engine provided with an exhaust outlet made according to our invention;

Fig. 5 is a plan view of an air-cooled engine provided with an exhaust outlet arranged within the cooling shroud for the engine; and

Fig. 6 is a plan view of an air-cooled engine similar to that of Fig. 5 but showing the exhaust being discharged against the stream of cooling air.

In the preferred form of our invention the exhaust outlet is applied to a water-cooled engine for a lift truck and in the modifications of Figs. 4 to 6 inclusive the invention is applied to an air-cooled engine. It will be understood as the description proceeds that although the invention is particularly useful in connection with lift trucks it may be applied to other vehicles powered with internal combustion engines such as tractors, trucks and the like that may be used in an area containing combustible materials.

Industrial lift trucks, enjoying wide current use, correspond to the device shown in Fig. 1 wherein the lift truck in its entirety is indicated as at 5 which is provided with steering wheels 6 and 7 and the forward drive wheels 8. In such lift trucks the mast 2 and lift fork 3 is in front of the operator who drives the truck from his operating position on seat 11. Directly behind the operator is mounted the internal combustion engine which provides the power for propelling the lift truck and the power for the hydraulic gear to raise and lower the lifting forks 3 and elevate the mast 2 carried by the lift truck. Such trucks are frequently used in and around cotton baling equipment, cotton warehouses and in the handling of oils, gasoline drums and other highly inflammable products. As will be noted from Fig. 1, the radiator of the lift truck is disposed at the extreme end of the truck as indicated at 20. The radiator filler cap 21 is exposed above the radiator 22. Supported within the shroud or cover 20 for the radiator is a frame 23 outlet 25.

3 surrounding the rectangular opening in the shroud and the frame 23 supports a coarse mesh screen or grille 24. Within the frame work of the shroud and grille and supported by the grille is an inclined upwardly disposed exhaust outlet 25.

The environment of the present invention includes the arrangement shown in Fig. 2 wherein an engine indicated at 30 is provided with an outlet 31 for the water or other coolant through hose 32 to the top header 33 of the radiator 22. The radiator includes a bottom header 34 and a core 36 connecting the top and bottom headers. The bottom header 34 is provided with an outlet 35 leading the water, which has been cooled by the radiator back to the engine block 3d. A radiator core shroud indicated at 37 extends rearwardiy from the core 36 of the radiator and surrounds the tips of the blades of the fan 38. The fan 38 is driven by means of pulley 39 and belt 442a going to a pulley (not shown) driven by the crankshaft of the engine. The pitch of the fan blades is such as to drive air from the engine compartment rearwardly and outwardly of the lift truck as indicated by arrows 41 and 42.

As will be understood by those familiar with the lift truck art, the cool air is drawn from beneath the vehicle and moves upwardly into the engine compartment and thence outwardly through the radiator core 36 and the grille 24. The engine is provided with an exhaust manifold 44 having an outlet 45 connected to a mufiier 46. The muffier in turn is provided with an exhaust outlet 47 which is connected to conduit 48 leading to an elbow 49 connected to the upwardly disposed exhaust The exhaust outlet 25 is provided with a cap 50 welded to the end of the member 25 and the cap is secured as at 51 to the frame 23 of the radiator grille. On that side of the exhaust outlet 25 disposed adjacent the core 36 of the radiator, the tube 25' is provided with two'series of small openings arranged so as to discharge the exhaust against the relatively cool closely spaced metal surfaces of the radiator core.

In the embodiment of the invention illustrated in Figs. 1, '2 and 3 there are seventeen openings 54 and a like number of openings 55 disposed at about 90 from each other about the axis of the tube 25. The size and number of the openings 54 and 55 are such that the combined areas thereof exceed the area cross-sectionally of the tube 25 and thus no pack pressure results in an amount sufiicient to adversedly afiect the operation of the engine 36).

In the showing of Fig. 3, the air from the fan indicated by the arrows 45B is driven through the passageways 36a in the radiator core 36 and such air as emerges from the core as at 42 meets the exhaust gas emerging from the openings 54 and 55. The exhaust gas coming through the ports 54, 55 is indicated by the arrows 54a and 55a. The volume and velocity of the air coming from the radiator diffuses with the exhaust gas and cools the gas so that by the time the exhaust gas and the air from the radiator reach the grille 24 the temperature of the mixture is well below any temperature which may ignite combustible material at the exterior of the radiator grille. As will be understood, particles of carbon and the like are often entrained in the exhaust gas and are incandenscent when discharged from the muffler. Such sparks are cooled and extinguished by contact with the relatively cool metal surfaces and by the air from the fan in the device we have provided.

It will be understood that elongated slots or other form of opening may be employed to direct the exhaust toward the radiator core to perform the function of the openings 54 and 55. It will also be understood that bafiles may be employed to direct the exhaust gases, sparks and flames against the metal surfaces in the radiator core.

In that form of the invention illustrated in Fig. -4 an air-coiled internal combustion engine 60 having cooling fins is disposed within an air-cooling shroud 61*having an inlet 62 for cooling air and an outlet 63 for discharging the cooling air from the shroud. A fan 64 powered by the engine is arranged within the shroud adjacent the inlet 62 and moves cooling air against the radial fins characteristic of air-cooled engines and drives said air toward the outlet 63. The engine 60 is provided with an exhaust manifold 65, a muffier 67, an exhaust outlet pipe 68 having openings 69 for discharging the exhaust toward the outlet 63. According to this form of the invention the grille in the outlet 63 of the shroud "is cooled by the cooling air moving in the directions indicated by the arrows 61a. The exhaust outlet pipe 68 is constructed substantially as in the preferred embodiment and the area of the openings 69 equals the cross section area of the pipe 68 so that the exhaust is discharged without back pressure against the relatively cool metal surfaces of the grille in the outlet 63.

A further modification of the invention for an aircooled engine is illustrated in Fig. 5 wherein an aircooled engine 70 is provided with a cooling shroud 71, an inlet 72 for cooling air and an outlet 73. The engine 70 is provided with a fan 74 which draws cooling air through the inlet 72 and discharges such cooling air over the cooling fins on the engine 70 and thence through the outlet 73. The engine 70 is provided with an exhaust manifold 75 leading to a muffler '76 and thence through an outlet pipe 77. The pipe 77 in this form of the invention is disposed on that side of the engine opposite the exhaust manifold and the pipe 77 is provided with outlet openings 78 discharging the exhaust against the cooling fins on the engine 76. The result of the opera tion of this form is that sparks and flame discharged from the openings 78 are quenched by contact with the cooling fins and thereafter are diffused and mixed with the cool ing air moving from the inlet 72 to the outlet 73 so that by the time they are discharged from the outlet 73 the mixture of cooling air and exhaust is at a temperature low enough so that it will not ignite combustible materials near the outlet 73.

A third fornr of our inventionsuited for use on *an air-cooled engine is illustrated in Fig. 6 wherein an aircooled engine 80 having cooling fins is provided with a cooling shroud 81, a cooling air inlet 82 and a cooling air outlet 83. The engine 89 is provided with a fan 84 to move air from the inlet over the engine and thence to the outlet 83. The engine 80 is provided with an exhaust manifold 85 leading to a muffler 36 and thence to an outlet pipe 87. In this form of the invention the outlet pipe 87 is provided with a series of openings 88 to discharge the exhaust gas against the cooling fins on the engine 80 and into the path of oppositely moving cooling air moving towards the outlet 83. The sparks and flames hit the cooling fins and are quenched before being diffused in the cooling air.

It will be observed that in all forms of our invention a fan for moving cooling air is driven by the engine and the relatively large volume of such cooling air is effective to cool spaced metal surfaces. The exhaust from the engine is discharged against such surfaces and into said mass of cooling air. In all forms of the invention except that of Fig. 5, the openings from the exhaust outlet discharge the exhaust in a direction opposite to the direction of movement of the cooling air. It will be understood that inthe conventional motor vehicle air is pulled into the engine compartment through the radiator somewhat like the showing of Fig. 5 where the fan 74 moves the air from the inlet to the outlet. Our invention may be used in such conventional air flo'vv arrangement by directing the exhaust against the radiator core and in a direction opposite the fiow through the core.

That-form of the invention shown in Figs. 1. 2 and 3 has been extensively tested by a laboratory for insurance underwriters. In conducting such tests the arrangement illustrated has beenmodified by placing a spark plug in the exhaust system and o'peratingthe engine soihatintcrmittently quantities of raw gas are pumped into the exhaust lines and there ignited by the spark plug. This produces a very severe or extreme condition of after fire. Combustible materials such as an open bale of cotton placed near the radiator grille have not been ignited during such tests. The sparks and flame were cooled by contact with the closely spaced relatively cool metal surfaces of the radiator core which was cooled by the fan.

During operation of the device it is found that sparks of considerable mass, may due to their momentum be discharged into the radiator core 36 and there cooled by contact before being carried in an opposite direction out through the radiator grille. Smaller and lighter sparks do not appear to go into the core but such sparks due to their lower mass are cooled by the air without coming into contact with the radiator core. Such sparks are cooled to a safe low temperature before being carried outwardly through the radiator grille 24.

Although we have shown and described a preferred form and three modifications of our invention in considerable detail, it will be understood that numerous changes may be made in the specific arrangements shown without departing from the scope of the invention as defined in the following claims.

What is claimed is:

1. In combination an internal combustion engine, a radiator for fluid for cooling the engine, a fan driven by the engine to move air in one direction through the radiator, an exhaust manifold, an exhaust outlet connected to the manifold, said outlet comprising a tube extending across the radiator in the path of the air being moved through the radiator by said fan, said tube having discharge means along that side of the tube most nearly adjacent the radiator directing sparks and flame carried by the exhaust against the radiator and in opposition to the air being moved in said one direction through the radiator whereby sparks and flame carried by the exhaust are extinguished.

2. In combination an internal combustion engine, a radiator fo'r fluid for cooling the engine, said radiator having air passages therethrough, a fan driven by the engine to move air through the said passages in said radiator, an exhaust manifold, an exhaust outlet connected to the manifold, said outlet comprising a tube extending across a portion of the radiator and in the path of the air being moved through the passages in the radiator by said fan, said tube having discharge means along that side of the tube most nearly adjacent the radiator directing sparks and flame carried by the exhaust against the radiator and in opposition to the air being moved through the radiator passages by the fan whereby sparks and flame carried by the exhaust are extinguished.

3. Fire prevention apparatus comprising an internal combustion engine, a radiator for said engine, a fan for moving air in one direction through the. radiator, a protective grill mounted adjacent the radiator, an exhaust outlet tube connected to the engine and mounted across the radiator between said grill and radiator, said outlet tube having discharge means on the wall of the tube most nearly adjacent the radiator to direct sparks and flame carried in the exhaust gas in an opposite direction against the radiator and against the air being moved through the radiator to extinguish said sparks and flame.

4. Fire prevention ap aratus comprising an internal combustion en ine, a radiator for said engine, said radiator having cooling passages therethrough. a fan driven by the engine for dischar ing air throu h the radiator passages, a protective grill mounted adiacent the radiator. an exhaust dutlet tube. said outlet tube being connected to said en inasaid outlet tube having discharge means on the wall of the tube adiacent the air discharge passages to direct sparks and flame carried in the exhaust gas against the radiator and in opposition to the air being discharged through the radiator passages to extinguish such sparks and flame, said passages in the radiator discharging a volume of air exceeding the volume of exhaust.

5. Spark and flame elimination apparatus comprising an internal combustion engine, a radiator for cooling said engine, said radiator having a core with passages therethrough, a fan driven by said engine to move air through said passages in the core, an exhaust outlet for said engine mounted across the radiator in the path of air being moved through said passages, said outlet having discharge openings to direct the exhaust toward said radiator and in opposition to the air being moved through said passages to extinguish incandescent carbon particles and flame carried by the exhaust gas.

6. Spark and flame elimination apparatus comprising an internal combustion engine, a radiator for cooling said engine, said radiator having a metal core with air passages therethrough, a fan to move a volume of air through said passages in the core in one direction, an exhaust outlet for said engine mounted across the radiator in the path of air being moved through said passages, said outlet 7 having spaced discharge openings to direct a lesser volume of exhaust toward said radiator and in an opposite direction to the air being moved through said passages to extinguish incandescent carbon particles and flame carried by the exhaust gas.

7. Spark an'd flame extinguishing apparatus for an internal combustion engine comprising a heat exchange radiator for fluid coolant connected to the engine, said radiator having a metal core with spaced passageways therethrough for cooling air, a fan to move cooling air in one direction through said passageways, said engine having an exhaust manifold, an exhaust pipe connected to said manifold, an exhaust conduit connected to said pipe, said conduit being mounted transversely of said radiator core and in the path of cooling air moving through said passageways, said conduit having exhaust discharge means directing sparks and flame carried by the engine exhaust against said metal core and in opposition to the direction of the path of cooling air moved through said passageways to extinguish said sparks and flame.

8. Spark and flame extinguishing apparatus for an internal combustion engine comprising a heat exchange radiator for fluid coolant connected to the engine, said radiator having a metal core with spaced passageways therethrough for cooling air, a fan to move cooling air in one direction through said passageways, said engine having an exhaust manifold, an exhaust pipe connected to said manifold, an exhaust conduit connected to said pipe, said conduit being mounted transversely of said radiator core and in the path of cooling air moving through said passageways, said conduit having exhaust discharge opening means directing sparks and flame carried by the engine exhaust against said metal core and in a path opposing the path of cooling air moved through said passageways.

9. Spark and flame extinguishing apparatus for an internal combustion engine comprising a radiator for cooling the engine, said radiator having a core with cooling passages therethrough, means for moving cooling air through said passages in one direction, said engine hav ing an exhaust outlet, said outlet having means adjacent the radiator core discharging the exhaust against the radiator in a direction opposite said one direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,112,534 ,Keen 2 Mar. 29, 1938 2,179,894 Malczewski Nov. 14, 1939 2,197,854 Eckert Apr. 23, 1940 2,382,386 Arms Aug. 14, 1945 2,612,745 Vecchio Oct. 7, 1952 2,692,024 Burdett et al Oct. 19, 1954 

